


it is the dawn; time has shifted

by Edgebug



Category: Back to the Future (Movies)
Genre: Don't Examine This Too Closely, M/M, borrows concepts from bioshock infinite (or one of them), don't need to have played Infinite though, healthy family units, weird metaphysical shit
Language: English
Status: Completed
Published: 2015-12-31
Updated: 2015-12-31
Packaged: 2018-05-10 13:41:14
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 16,184
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5588089
Author URL: https://archiveofourown.org/users/Edgebug/pseuds/Edgebug
Summary: <blockquote class="userstuff">
              <p>The flux capacitor shakes, screams, explodes. Marty and Doc deal with the aftermath.</p>
            </blockquote>





	it is the dawn; time has shifted

**Author's Note:**

> this kind of just Happened, i just held on and yelled the whole time.
> 
> takes place in an AU that assumes that Doc's DeLorean didn't get hit by lightning at the end of Part II and they made it back home just fine (and continued going on reckless adventures). aaand that's all the backstory you need to know

There is this space--

\--not the right word, not really, it's more like a lack of space, it's the liminal sliver outside the universe and looking in, outside it all--

There is this space when you time-travel where time is nonexistent, where you are beyond its grasp. It is the space where you look at the fabric of the universe, of spacetime; the space where you jump from point to point, fold time like wet paper and punch a hole through, just big enough for yourself. It's the space between point A and point B, the moment right after you dematerialize and right before you begin to exist again.

There is this _space_.

_"Doc, do it, floor it!"_

_"There's too much of a charge in the capacitor! If we let it go now we'll--"_

_"It's our only shot! Do it!"_

_The DeLorean's motor revs harder and the car disappears, leaving their pursuers in their flaming wake._

The flux capacitor screams, flickers, explodes. The car and everything else inside is whisked away, torn atom from atom and scattered.

It doesn't hurt.

It doesn't feel like much of anything, at first.

Marty McFly comes back to consciousness slowly, gradually. He breathes like the expansion and contraction of a galaxy. He exists everywhere. He exists nowhere.

How long has he been here?

It is impossible to even begin to tell.

 _I gotta pull myself together_ , he thinks, and almost laughs at his own joke. Not that he has lungs to laugh with. _What_ _the fuck happened?_

_Figure it out later, Marty. Get all your bits in one place first. Then find Doc._

Is Doc alive?

Is _Marty_ alive?

 _This is heavy_ , he thinks, slowly, pieces of his mind weaving together sure and steady. More memories coalesce, more pieces of the puzzle slot into place.

Some of Marty is nearby Alpha Centauri. Some of him is near the twenty-fifth century. He finds a piece close to the Industrial Revolution, another close by the Hourglass Nebula. A good few pieces are circling Hill Valley, 1986. They scream for home, terrified and out of place, and Marty brings them close, lets them join the safety of his collective.

 _Can't go home yet_ , he tells himself, though he feels like he could if he only drew his collective closer to the point that is Hill Valley. _We've got someone to find first._

There is this space, vast and unknowable, and you aren't supposed to get stuck there, but when have Doc and Marty ever done what they were supposed to do? Marty plucks bits of himself from the ether but he feels held together by luck and a prayer, nothing keeping him intact but force of will. He's got to find Doc. He has enough of himself together now that he thinks--he thinks he can afford to send some of himself off from his main cluster to look for Doc. He stretches out, expands over space and time, sends feelers out across dimensions and into the infinite darkness.

Time doesn't exist here. It might be seconds or it might be milennia. It is impossible to judge.

It feels like a long time, maybe.

He finds a fragment of Doc, glowing bright in the dark. He can't see so much as feel and he touches the little spark, rushes his entire collective toward it. There's more of him close by; he and Marty meet like clouds, like galaxies, overlapping. He can't truly hear Doc but he can feel him--excitement, wonder, questioning, a mile a minute.

_look where we are Marty we can see everything we can see the universe_

_I know, Doc, but we gotta go home. We gotta try._

Doc's light pulses.

_but we could go anywhere see anything we could know it all all the secrets of the universe laid out for us just for us Marty you and me_

Doc's thought process is wild and excited and shaky. Anguish, not his own, mists up Marty's perception. Doc wants to stay, and Marty is terrified.

 _Who's gonna feed Einie?_ he thinks, frantic, _C'mon, Doc, we gotta go home. We've been here too long already. You can't just stay here! You can't leave me._

The anguish dissipates as instantly as it showed up. Warmth pulses from the center of Emmett's consciousness, love, indulgence, resignation. He can feel the expansion of Emmett's being, a sigh, before it curls up around Marty's own.

_yes Marty you're right Marty_

_anything for you_

Then, longingly,

_the universe will wait for me._

-

Marty gasps awake, gripping his sheets. He flexes his fingers, white-knuckling the bedclothes; he swallows around nothing, takes in deep breaths, stretches out his legs.

For a moment he is disoriented, panic rises like bile in his throat. The light is too bright, the sounds are too loud. Marty can't remember much about the dream he had--only bits and pieces--but the last thing he knew, he was with Doc, escaping from two men pursuing them in the early nineteen-tens.

When is he?

He scrambles to a sitting position, paws for the clock on his side table. Eight AM, February the sixteenth. Sunday. Marty gives a relieved sigh; good, they ended up back where they're supposed to be, and judging by the state of Marty's room, everything is the way it's meant to be.

Christ, how's Doc? Marty lurches upright and nearly falls over, holding out his arms to balance himself. God, is this what a hangover feels like? "Jesus, what happened last night," he mumbles once he's caught his balance, stomping into the main part of the house. Nobody else is home and Marty shoves a pop-tart between his teeth before kicking on his shoes and skidding straight out the door.

 -

The keys are under the mat as usual and Marty lets himself in without hesitation. He steps in, instantly calls out. "Doc! You here?"

"Here, in here," Marty hears, but Doc's voice sounds subdued; Marty rushes into the lab, the source of the sound. Doc's sitting on his bed, looking--blank. Defeated.

"Doc?" he asks, slowly, "I--are you okay?"

"Oh?" Doc looks up at him, frighteningly still and un-animated. "Yes, yes, I'm fine. Are you?"

"Yeah, I'm just--I've got a bit of a gap in my memory, is all, I was hoping you'd be able to fill me in?"

"Where does that memory gap begin?" Doc asks, sharp dark eyes fixing on him. "What do you remember? Be detailed. I want to know if we remember the same things. If our memories differ then we know our minds were truly rattled."

"Um--we were hanging out in 1914," Marty says slowly, "we wanted to see some Charlie Chaplin flick, in the theater, right?" Doc nods. "After the movie, we, uh..." Marty blinks at the memory, trying to recall it in the right order. "Mr. Fusion was giving us trouble when we tried to get home. Put too much power in the capacitor, or something. Burnt out our hover circuits too. You were worried that if we didn't fix it before we made another time jump then something bad could happen."

"So far we remember the same things. Go on?"

"Some goons showed up. I think they wanted the DeLorean. Said it looked like some fancy automobile and they wanted it real bad. They chased and when they started shooting we floored it to 88."

"Is that the last of your memory?"

"Yeah. Next thing I know I'm waking up this morning."

Emmett gives a troubled frown. "I have the exact same memories and the exact blank space, Marty," he says, and stands up. "Though I suspect I know the reason."

"What is it?"

Doc steps closer to Marty. "Follow me," he says grimly, brushing past, and Marty nearly trips over himself in his hurry to follow.

He's got the DeLorean parked out back. "There she is," Marty says, "I'd been wondering--"

"Look inside," Doc says, and he sounds about a million years old. Oh, no.

Dread fills Marty as he steps closer and reaches to open the gull-wing driver side door. He bends to look inside and instantly notices bits of broken, frosty white glass dusting the upholstery. "No," he murmurs, eyes flitting to the flux capacitor--or what used to be the flux capacitor. "Oh, god, no."

"The DeLorean is now an absurdly large paperweight," Doc says, and his voice is more terrifying than if it were _grieving_. It's just _empty_. "Nothing more."

"Jesus, Doc," Marty murmurs. "I'm--I'm _sorry_. Can you make another?"

Doc shrugs. "I think this is the universe's way of telling us no more temporal joyrides, Marty," he says. "As for the memory gap, I think the charge from when the capacitor exploded is responsible. It's a wonder we survived at all, and a miracle it didn't scramble our brains further." Doc looks somehow tiny, standing there in his deep-green long coat, arms curled around himself. "I suppose it could handle two bolts of lightning, but not the output of a malfunctioning fusion reactor."

He hates seeing Doc like this. Marty steps over and throws his arms around Doc, hugs him tight. Doc stiffens, surprised for a second like he always seems when Marty hugs him before melting, as he always does, and wrapping his arms around Marty in return.

_Marty sorry wish it had been different wanted it different Marty sorry don't deserve you_

"Doc, shh, it's okay," says Marty, and Doc freezes once again.

"Hm?" He draws back a bit. "I didn't say anything."

Marty blinks. "Thought I heard something." He shakes himself, gives Doc a quick squeeze before pulling back. "Alright, no more time traveling. There's gotta be something else that'll keep your attention."

"I'm sure I'll find something, Marty," Doc says, a faint, sad smile on his lips. "Maybe I'll see if I can reverse-engineer that hoverboard of yours. I got sort of addicted to being able to fly, you know."

"Yeah, that shouldn't have any negative consequences," Marty says with a small laugh, and Doc grins his wild, excited grin in return, and Marty thinks that everything just might be okay.

-

Marty knows that when two people go through a harrowing experience together, they bond--and God knows they just went through yet another one of those. He also knows that he and Doc have saved each other so many times that they just feel plain safe around each other; protected, they have each other's backs.

Whatever the reason, especially so tonight, Marty doesn't want to leave Doc's garage. He's been hanging around all night as Doc's been following through on his idea to reverse-engineer the hoverboard, just spending time with him, tidying up various messes around the lab, rough-housing with Einstein. It's getting to be late, though, a quarter of midnight, and Marty could crash here but his mom will probably flip if he isn't home in the morning. He's sitting down next to Doc now, watching him carefully dismantle the hoverboard and poke around its inner workings.

"I should go," he says, making no move to get up at all.

Doc's brow furrows. "I suppose you should," he sighs. "Would you hand me those needlenose pliers?" Marty reaches across the table to grab them before handing them to Doc. "Thank you," Doc says, fingers brushing against Marty's as he takes the pliers from him.

_Jesus Christ, I wish I didn't have to leave._

"Then don't," Doc says as he gently detaches a wire with his pliers. "Call your mother in the morning and tell her where you were."

Marty's eyes widen. "Don't what?" he asks, and Doc fixes him with a look.

"You said--"

"I didn't say anything," Marty says.

"I clearly heard--" Doc blinks, shakes his head. "Sorry. I must be hearing things. It's late."

Marty feels shaken. Doc's words had exactly fit with his train of thought, as if Doc really could read his mind. "I think I am gonna go, Doc," he says, "I could call in the morning but I'd catch hell."

"Then it's probably for the best, don't let me be a bad influence," Doc says with a twitchy smile before he stands up and walks Marty to the door.

"I'll see you tomorrow after school," Marty says automatically, "okay?"

"Of course," Doc says, and gently claps Marty on the shoulder. "Travel safe, kid. Call me when you get home so I know you made it in one piece."

"You got it, Doc," Marty says with a lopsided grin before ducking out the door and grabbing his skateboard from where it was propped up against the garage's siding.

He skates off into the night and tries really hard not to think about how his shoulder is still prickling comfortably where Doc tapped it. He also tries not to think about the wave of affection rolling across his mind the second they made contact.

-

"Now, Marty, I know you're almost an adult but if you plan to stay out past midnight I'd like for you to at least tell me first," Marty's mom gently scolds him over breakfast the next morning, and Marty nods, sighs.

"Yeah, yeah, Mom, I got--" A pause. "Wait, mom, _almost_ an adult? I turned eighteen last year!"

Lorraine laughs, fixes him with a look; she butters her toast with swift precision as she speaks. "Nice try, mister," she says, and Linda snorts a laugh too.

"Marty, if you're gonna lie about your age, go for broke and make yourself 21 so you can at least _drink_ ," she drawls, and Marty shuts the hell up.

Well, if he and Doc fucked up the space-time continuum again, changing the year of his birth isn't that bad a screw-up, right? Things could be worse, Marty knows that first hand. Definitely something to mention to Doc, though. What other weirdness has been inadvertently wreaked this time?

Not that they have a time machine to fix it with, now.

-

"Doc," Marty says as soon as he's through the door to Doc's garage, "do you know why my folks think I'm still seventeen?"

Doc doesn't even look up from the hoverboard. It's in shambles now, but Doc seems to be having a good time. "Maybe they forgot your birthday. How was school?"

"No, no, they didn't forget, Doc! I had my eighteenth birthday this year and today at breakfast my mom and sister swore up and down I was still seventeen!"

Doc fixes him with a look, finally, raising his safety goggles up to his hairline. "Give me your wallet, please," he asks, and Marty digs in his back pocket before tossing the wallet across the garage; Doc catches it easily and flips it open.

A tense few seconds pass before Doc sits up a little straighter, squints at the license inside a little closer. "What? What is it?" Marty asks, darting over, and Doc flops back into the chair, drops the wallet on the table.

"Great Scott," he says, "according to your license, Marty, your birth year is 1969."

"Bullshit," Marty says, grabbing the wallet up from the table and flipping it open. "Marty McFly, date of birth--shit. Okay, great, so my parents had me a year later. That's not so--"

"That's impossible, Marty, if they'd had you a year later you wouldn't exist," Doc says, eyes wide and darting back and forth. He's talking to himself now, muttering; he stands abruptly and begins to pace back and forth.

"Whaddya _mean_ I wouldn't exist?!" Marty asks, incredulous, "Doc, you gotta explain this to me, okay?"

"Explanation I can do, and that's the simple part of all this: if your parents had waited a year or even a month, the egg that you would become would have long-since been dead. You'd be an entirely different person--in fact, not Marty McFly at all," Doc says quickly, like his words are tripping over one another in their hurry to get free. "No, this is--" A pause. "I don't know what this is," he says, staring into space and stilling his footsteps, and Marty blinks for a few seconds.

"What about your license?" Marty says after a moment. "Is it fucked up too?"

"I don't know why it would be."

"Why would _mine_ be? We're the only ones who've been time traveling. I don't know, just--just check it?"

Doc stands up and moves to his bedside table, picks his wallet up. "Well," he says, after a long second of staring at the inside, "damn."

Doc sits heavily on the bed, and Marty sets down next to him. "It's changed too, isn't it," Marty says, grimly. "Doc, what does this even mean?"

"Beats the everloving shit out of me," Doc says. "It's impossible that our actual birth dates were moved up. What could have happened in the past to make our licenses change?"

"Is it just our licenses?" Marty asks. "What about, I don't know, birth certificates and stuff?"

"Let's find out," Doc says, "do you know where your parents keep your birth certificate?"

"Not a clue," Marty says, "and if I ask for it they'll ask questions and--"

"I don't know where mine is, either. To the Office of Vital Statistics, then," Doc says, standing up, "and maybe the library, we can look up your birth announcement."

"Alright, Doc. You said the DeLorean's a paperweight, does it at least move three-dimensionally?"

"Oh, absolutely. Come on, Marty, there's a mystery to solve!"

-

Getting their birth certificates involves a lot of waiting in uncomfortable chairs in the Hill Valley Office of Vital Statistics while a flunkie pores through cabinets of microfiche.

"This will be much faster after the advent of the Internet," Doc says to Marty under his breath, and Marty looks at him quizzically. "Every computer will be connected and information will be transferable and retrievable instantly," Doc explains, and Marty nods. "Unfortunately, that's about four or five years off. More 'til it becomes really big."

Marty's sitting right next to Doc; there's no arm rests on these shitty chairs, so Marty leans lightly against Doc's shoulder instead. He can sense Doc's anxiousness, something in him trembling like a bird in a cage too small for its wingspan. Doc's grounded in three dimensions, now, and he's feeling it acutely, Marty just knows.

 _There's a whole world out there, Doc, and you can see it all,_ Marty thinks. _You're just as free as you were before._

He feels Doc sigh softly and relax at least somewhat, not pulled tight as a guitar string anymore. It's a second of quiet before Marty speaks. "What other cool future stuff can you tell me about?"

"Oh, plenty. We should go--" Doc pauses, seems to deflate as he remembers they can't just go see things anymore. "You'll find out sooner or later, I'm sure."

Soon enough the clerk has the copies of their certificates; Marty picks his up and hands Doc his, staring down at it and searching for the date of birth. "Exactly one year late," Doc breathes, "right on the tick. I'm guessing yours is the same way?"

"Yeah, Doc, but what does it mean?"

"But is it in our birth announcements?" Doc's pacing back and forth. "C'mon, Marty, to the library!"

Doc flings himself toward the exit and Marty scrambles to catch up. Doc moves fast and with all the coordinated grace of a puppy learning to walk, but Marty doesn't mind.

-

"This will definitely be much easier after the Internet," Doc groans, flicking through stacks of archived newspapers. "You'll just be able to put in your search terms and the computer will do all the work, instantly."

"That's great, Doc," Marty says absently and tugs out the paper for the day after his birthday in nineteen sixty-nine. He starts poring through, and Doc makes another miffed noise.

"Well, yours isn't in your birth year at all," Doc says, "so--"

"I found it. Martin Seamus McFly. Born in nineteen sixty-nine."

"The day of your birth hasn't changed, just the year. I can only presume mine is the same."

"This is heavy," Marty mumbles, running a hand through his hair. "Well, okay, let's look at the bright side here," he supplies, "at least we're not in some nightmare parallel timeline where Biff is, I don't know, dictator of the world."

"Yes, but I hate having an unsolved mystery," Doc says bitterly, "and I can't seem to understand how to even begin solving this one."

"I know, I know you do." Marty gently takes the papers from Doc's hands, slides them back onto the shelf where they belong. "Looks like this one just doesn't wanna get solved, Doc. As it is--we're here, we're fine, so is everyone else. As for the birth dates..." Marty shrugs. "The universe is pretty messed up," he says, finally, "let's just leave it at that."

Doc actually smiles, a laugh in his voice when he responds. "Indeed, Future Boy. The universe is pretty messed up."

-

Marty gasps awake at four in the morning, memories of the dream lingering with him even as he stumbles back into reality. It wasn't as if it was a scary dream, it was just _endless_ , reaching out into the dark. He breathes slowly, stretches out in his bed. In the dream he felt as if he was dissolving, parts of himself sliding off irretrievably, so it's comforting to revel in the sensation of having a body.

Marty's throat feels scratchy and dry. He groans; he wants nothing more than to stay in his bed, warm and soft and comfy, but the need for water is overpowering his need for warmth. He swings his legs over the edge of the bed and climbs out, padding down the hall and into the kitchen. He flicks on a light in the kitchen and it instantly blares in his eyes and it's too much all at once, painfully bright. He hisses and flicks the light back off, instead opting to turn on the softer, smaller light above the stove before grabbing a cup from the cabinet and approaching the fridge for some water. He's halfway through his second gulp, blinking the spots from his eyes, when he notices his hand doesn't look quite as solid as it should.  
  
He almost drops the glass, catching it after he fumbles and setting it, shakily, on the counter. His instinct is to scream for help but he can't, he _can't_ , what's he going to tell his family? Marty slams on the big light switch again, every kitchen light coming on at once. He holds up his hand between his eyes and one of the bulbs to try and judge the transparency, and--yeah, he can definitely see light through his hand. It's wavering in strength, but it's there.

"Jesus Christ," he says weakly, stricken as he watches the opacity of his own hand shift and morph. After a second, it stops shifting and Marty's left with an opaque, solid hand again. "What the _fuck_ ," he breathes, and it's four in the morning but he's terrified, his heart is hammering in his chest so hard it hurts.

It's four in the morning and he sure as hell isn't staying in this house. He has to go to Doc, ask what's going on--see if he's alright. Doc's the only other person in the world who's going to understand. Marty goes back to his room only long enough to yank on a pair of pants and throw a shirt over himself before skirting back out into the main area of the house, kicking on his shoes and carefully, as carefully as he can, opening the front door to slip outside.

The front door squeaks in exactly the same way it always did, no matter the timeline; Marty knows just how to hold it so that it stays silent. He closes it back up without a sound and grabs his skateboard from where it had been leaning. He could take his truck, but the garage door opening would wake up his family. There's no cars on the road at four in the morning in Hill Valley, so Marty's just going to have to ride it the old fashioned way, no bumper-surfing.

He makes good time, and he stays miraculously opaque all the way to Doc's garage. He doesn't knock on the door, he never does, he just fishes for the key under the mat and lets himself in. "Doc!" he cries, "I know it's late, and I'm sorry, but--"

He sees Doc sitting at his work table, idly studying his own hand. Doc instantly looks up at him, shock registering on his face before it settles down. "I thought you'd sleep through the worst of it," he says, sounding apologetic, "if it was happening to you too."

"What's happening to us, Doc?" Fuck. Fuck, it's happening to Doc too. They're fading out, just like Marty did onstage in nineteen fifty five, but there's nothing to save them now, they're--they're--

The panic must have been evident on Marty's features; Doc's hands alight at his shoulders, squeezing tight. "Marty, calm down, we're fine," Doc says, firm but comforting. "We are not fading out of existence. I have proof."

He lets go of Marty just long enough to grab something from his table, holds it up in front of Marty. It's a Polaroid of them both. "Just as solid as ever," he says, "we haven't wavered once on film, even when we were in real life. This can only mean that we aren't fading from the space-time continuum, Marty, we're both here and well."

Marty gulps in a few breaths, deep and gasping; he nods a few times, tries to will himself to stop shaking, tries to will his heartbeat to slow down to something more manageable. He steps forward and flings his arms around Doc's neck, raising on tip toe to do it. Doc is warm and solid and real in his arms and it's exactly the reassurance Marty needed, and Doc circles his own arms around Marty, holding him tight. "We aren't going anywhere," he says firmly, and Marty nods.

"I guess we've just gotta--gotta ride out this weirdness, huh?" Marty says once he pulls back, hiccuping just a little, and Doc shrugs.

"I have a theory, but it really isn't worth talking about until it's confirmed." Doc pauses. "I'm glad you came here, Marty, though I'm sorry you were frightened so. I didn't want to call to check in, again, I'd hoped you were sleeping through it."

"Had a bad dream and woke up." It's nearly four forty-five in the morning now and Marty doesn't want to go home, damn the consequences. "Doc, can I just crash here?"

"You're more than welcome," Doc says softly, "as always."

Marty settles onto Doc's armchair and Doc brings him a blanket, drapes it over him, before he turns out the garage lights and settles in his own bed. Marty closes his eyes and tries to relax but he can't shake the fear that still clings to his brain.

He shivers like cold water is poured down his back and can't stop. _What if I'm not here in the morning? What if I don't exist in the morning?_

"Marty, are you all right?" Doc asks, abruptly interrupting Marty's thoughts.

"I'm--I'm fine, Doc," Marty says, quietly, haltingly. "Really."

"Mm." Doc sounds like he doesn't believe him. "Are you comfortable there?"

"I've crashed in this chair before."

"And you've complained of a stiff back in the morning before." A pause. "Would you like to sleep here beside me? I'm a still sleeper, I'm sure I wouldn't disturb you." A pause; Marty can almost hear Doc flinch. "Nevermind. Perhaps that was inappropriate. I didn't mean--I simply meant—I--Of course, there's the twin bed too, I--"

"I'd really like that," Marty interrupts him, relief flooding his system. He gets up and pads through the darkness toward Doc's bed, not even needing the light, his mental map of the space perfectly reliable. Doc moves over and Marty clambers onto the bed beside him.

"Better?" Doc asks, and this time Marty can hear him smile.

"Much better," Marty hums, and it's true--way better than the armchair. They're both fully clothed and curled up back-to-back, and Doc's throwing off warmth like a furnace, and the thing inside Marty that had been shaking in fear calms down, begins resonating a pleasant thrum instead.

"Good night, Marty."

_I'm here Marty don't worry we're fine sleep well I'm right here_

The calming thoughts whisper in the back of Marty's brain and they feel like Doc and Marty's too tired to think about it, too tired to do anything other than enjoy it and accept the comfort of it as he drifts off.

-

Doc seems to notice that Marty's awake before Marty even does. Doc excitedly cries his name and bounds over to the bed where Marty is blearily blinking sleep from his eyes and hazily wondering what time it is. "Marty!" he cries, sticking out his hand for Marty to look at, palm-out, "look!"

Marty fixes his eyes on Doc's palm. "What'm I lookin' at, Doc," he mumbles, raising a hand to wipe his eyes. "Your--your hand?"

"Watch this!" Doc's practically vibrating with excitement, and Marty drops his hand down to fix his gaze on Doc's own.

Across the span of about seven seconds, Doc's hand fades out entirely.

"Doc!" Marty cries, reaching out to grab at him, and instantly Doc's hand returns. "Doc, don't--what was that?!" A pause, "you--you predicted that happening!"

Doc shakes his head, grinning still. "No, Marty, I didn't predict it, I caused it! I can do it at will now!"

"Holy shit, Doc," Marty manages, willing his heart to start pounding, "that's--that's heavy. How--how did--" Marty's still sleep-hazed brain is trying to pull him six different directions; he splutters for a second before he settles on "You shouldn't do that! What if it's--what if it's dangerous?!"

"No, don't worry, I was able to come back! What if I allowed my entire form to dissolve? I--"

"Doc!" Marty cries, reaching out and gripping his shoulders. "For Christ's sake, be careful!"

"Of course! Of course," Doc says, and Marty forces himself to relax, just a little. He can /feel/ excitement pouring off Doc in waves, the joy at his own body being a new science experiment. "I will be the very picture of caution, Marty! Now--you have to get to school! And call your mother," Doc says, and moves haphazardly toward his work table, pulls some sort of sensing equipment out of a box.

His mom. Marty swears loudly and lurches out of bed, paws for the phone. This should be a fun call, Marty just knows it.

Marty's mom is miffed at first, understandably so. "Young man," she says, and Marty cringes automatically at the invocation of the _Mom Voice_ , "I _just_ told you that if you wanted to stay out past midnight you should talk to me or your father first and at least let us know where you are so we don't worry sick!"

"Mom, I'm sorry, I spent the night at Doc's. An experiment went wrong and I had to help him." The words burn in his throat even though they aren't entirely a lie--an experiment _did_ go wrong, the flux capacitor exploded and altered them somehow. Still, he hates lying to his mom, even by omission.

He hears her sigh crackle over the phone's speaker. She's calmed down a bit when she speaks. "Still, you should have called me," she says more gently, "okay?"

"Yeah, I know," Marty says, then adds with absolute sincerity "I'm sorry."

"Now you better get yourself to school. Have a great day, sweetie. I love you."

"Thanks, mom. Love you."

Marty hangs up and moves to the garage's back room to change into the set of clothes he keeps around Doc's--he learned to do that the first time he managed to spill some kind of noxious chemical on himself and had to shower off out back while Doc appeared to have a mild panic attack while on the phone with Poison Control. He'd had to go home wearing Doc's clothes, which wouldn't have been bad except they were about a million sizes too big. Best to keep a spare t-shirt and jeans around just in case.

When he returns to the main part of the garage he finds Doc with that sensing equipment set up and his hand underneath it. "I gotta get to school, Doc."

Doc doesn't look up. "Do you want me to drive you?"

 _Yes_. "No," Marty says, "thanks." He kicks his shoes on, moves to the door before he pauses, hesitates. "I know I've already said it but be careful, okay, Doc? Just be careful."

Doc does look up at him then. "I will be, I swear it."

"Just--" Marty jabs his index finger in Doc's direction, "--I'm gonna be _really_ pissed off if I come back here and find you've gotten yourself written out of existence! I'm gonna be _so_ \--"

Doc laughs, eyes crinkling. "I wouldn't want to incur your wrath, I will be careful, now get to school!"

Marty lingers in the doorway for a split second and he has the thought to just _fuck_ school and stay here, but he can't, and he pulls himself from the garage so that the thought can't tempt him further.

-

The Marty in this timeline has good grades and takes advanced classes. It's been rough to keep up with but he's doing pretty well, considering.

He doesn't go to Doc's after school, like every fiber of his being is screaming at him to do. Instead he goes home because he has a damn essay to write--he wants to keep up with those grades, thank you very much. He can do most of his homework at Doc's, but essays tend to take more focus than he can spare with Doc around and as energetic as a Jack Russell.

He ends up getting half of his English essay written. Sleep eventually takes him at a little past midnight, finding him curled on his bed and still in his clothes with one Nike still on his foot and the other hanging off his toe.

-

Marty wakes up slowly, warm and comfortable and floating in that pleasant, hazy space between sleep and awake. Soft, warm, someone's arm over him.

He shifts toward the source of the warmth, nestling closer. As he wakes up, it occurs to him a little more clearly that he's cuddled up with a person. He can hear their heartbeat, slow and steady. His ear is against their wide, solid chest. Marty's eyelids flutter, confusion washes across his hazy, sleepy thoughts.

There hadn't been anyone in his bed when he went to sleep.

Wait a minute.

He wakes up just enough to realize _it's Doc_ , and the shock of that thought wakes him up fully. His eyes snap open and he pulls back just enough to look up; Doc's asleep, in his bed, and there's Marty, also in Doc's bed. All his damn clothes are on and he's on top of the covers but he's on Doc's bed, cuddling with him, and holy shit, he can't remember getting here.

Part of Marty's brain whines something along the lines of _who cares? It's comfortable! You're comfortable! Figure it out later,_ and Marty has to actively fight against that loud section of his mind. Doc's arm is still around him. Doc's been holding him like a teddy bear for god knows how long.

"Doc?" he ventures, quietly, and Doc's eyes open, blink sleepily. "Doc, wake up."

Doc's dark eyes are swimming for a moment before he blinks several times and looks down at Marty. "Marty?" he asks, voice a raspy baritone from sleep, clearly puzzled.

_good here Marty here why? why here? how? don't care_

"I don't know how I got here," Marty says, and Doc blinks again.

"I know you don't," he says. Marty can feel confusion rolling off him, but also contentment. "It looks like we have another mystery on our hands."

Marty pulls back enough to sit up. But god, it had been hard--he wants nothing more than to keep _cuddling_ with the _Doc_ , and that's weird, right, but he can't bring himself to mind. "Okay," he says, shaking himself, "did I sleepwalk or something?"

Doc sits up as well, looks over Marty. "Unlikely," he says. "You're only wearing one shoe. Yet your sock is perfectly clean, so you can't have walked."

"Sleep-skateboarding?" Marty asks, desperately.

"Unlikely, but possible. Feel free to check around for your skateboard. People have been known to do far stranger shit in their sleep."

Marty lurches up from the bed and performs a cursory sweep of the garage. No skateboard in sight. He moves to the door, finds the deadbolt locked. He flicks it open and opens the door. Again, no skateboard. "This is getting kinda weird," he mumbles, and, on a whim, checks under the mat for the key. It's still there. "Forget how I got here," he calls back to Doc, "how the hell did I even get in? I didn't use the key!"

When Marty turns around Doc's already performing his own investigation, padding around the lab in his pajamas. "Nothing in here's been disturbed." A pause; Doc stares into the distance thoughtfully for a moment. "It's as if you just appeared out of nowhere."

"Wait a second, Doc, wait a second," Marty says incredulously, crossing the distance between them, "are you saying I _teleported_? In my _sleep_?"

Doc is _excited_ now, all wild eyes and energetic shakes. "Suppose you faded out entirely in your sleep and simply re-appeared here! It's possible that you just stopped being in one place and started being in another, just like that!" A pause. "It's just a theory, of course."

It's on the tip of Marty's tongue to say it sounds far-fetched, but the thing is that it doesn't, not after all the things they've been dealing with recently, not with the fading out and the bizarre changes to their birth dates and the weird emotion-reading incidents that Marty's been trying really hard not to think too much about.

"Pretty wild theory," he says weakly, "that's heavy stuff."

Doc's talking to himself at this point, off in his own world; he's pacing back and forth and obviously deep in thought and Marty's standing there in one Nike when Doc's clocks start chiming the hour.

Marty counts the chimes under his breath; they stop at eight, and Marty groans. "Doc!" he cries, interrupting Doc's one-man conversation, "I gotta get to school and I don't have my freakin' skateboard, you gotta drive me!"

-

"Marty, you're wearing one shoe and the same clothes you wore yesterday," Jennifer says as she sits down next to Marty at lunch, out in their spot on the quad. "Are you okay?"

God, is Marty glad he has Jennifer. It's good to have a trustworthy third party who knows all about the time travel bullshit; someone removed from the situation to get a relatively objective opinion from. Jennifer's good at objective.

"Yeah, Jen, I'm fine," Marty says. "It's just--I'm wearin' the same clothes because--" A pause. "Okay, this is gonna take some explaining."

Jennifer listens to Marty's recollection of the events since the DeLorean went kaput; she nods and makes the appropriate sympathetic sounds at the right times. Her eyes dart around, she delicately gnaws at her bottom lip, deep in thought.

"So you aren't seventeen," she says slowly.

"No, I'm not! I just told you I might have teleported in my sleep and you're hung up on--and we're in senior year, I can't be seventeen still!"

"Well, yeah, we're in senior year, but you're just a year ahead of me. Of everyone. You're smart." A pause. "And there's no way you _teleported_ , there has to be a _real_ explanation. You probably just walked it, Marty, or maybe you, I dunno, hitchhiked? Then you opened the door and put the key back under the mat before you closed it."

"I... guess that's possible."

"Of course it's possible." Jennifer shakes her head. "Okay, anyway, so you're seventeen in this timeline. Not a big deal, right? In a big-picture sort of way," she muses.

"You'd think, but Doc's a year younger too. He says there's no way we could actually be a year younger, it has to do with our documentation being tampered with rather than--"

"But why? Why would your documents be wrong?"

Marty shrugs. "No idea. That's what makes this so weird."

"Good thing you're used to weird," Jennifer says, eyes sparkling; she nudges Marty playfully with her elbow before she stands and tosses her garbage in a nearby trash can. "C'mon, we've got about two seconds before the bell rings. You think you can teleport us to math class?"

"Not funny."

"Beam me up, Marty!"

_"Jennifer!"_

-

Marty's skateboarding home the next day; it's after school and he's thanking whatever deity is listening that nothing particularly strange happened today. He has homework to do, and he doesn't need to start fading out again in the middle of his history assignment--or worse, in the middle of history class. He can hear it now, his humorless professor sending him to detention for trying to write himself out of existence.

His skateboard is almost an extension of himself--he can feel the seams and imperfections of the sidewalk under his wheels, he knows what spots of the pavement to avoid. He knows these routes inside and out, can take them automatically. His Walkman is singing loudly in his ears, blasting a tune Marty's heard countless times before.

Abruptly and out of nowhere, something inside Marty's chest seems to seize up and freeze solid before it shatters, pieces turning to dust and disappearing, leaving a gaping void behind. Something's _missing_ and it's sudden and beyond distracting and Marty just about crashes his skateboard, stumbling off of it and trying to quell the panic in his skull, doubled over with his hands on his knees.

"Holy shit," he gasps, managing to straighten back up. The initial shock of pain has dissolved, but he still can't shake the bone-deep feeling of _wrongness_ , the feeling that something crucial is missing, out of place.

Well, this is a new symptom, and whenever weird shit happens nowadays it's a good bet that the same thing is happening to Doc. _Doc_. He won't have answers, probably, but god, he's good at quelling Marty's anxiety, just by existing. That's the decision-maker, and Marty hauls his shaky self back onto his skateboard and takes off in the direction of Doc's garage.

-

"Doc! Hey, Doc!" Marty calls the second he has the door to the garage open. Einstein instantly comes to greet him, enthusiastically cramming his head against Marty's hand. Marty pets him automatically, eyes scanning the garage. "Doc!" he calls again, walking further into the garage, toward that small living-room area. Still no response. Einstein's panting anxiously; he whines and leans his entire body against Marty's legs, sticking like a burr to Marty as he walks. "He's gone," Marty says out loud, running a hand through his hair.

Something inside him feels _still_. Whatever it is that buzzes, resonates when he's around Doc has gone totally silent, and he's feeling it acutely. Doc's _gone_.

"Holy shit," Marty manages, and collapses into the helpfully nearby armchair. Einstein's still glued to him, visibly uneasy, and terror blurs Marty's vision.

Does Doc even still exist, or did he accidentally wipe himself out of the universe in his excited hurry to experiment with his newfound ability to fade in and out? Marty tries to calm himself. No, he can't be out of existence entirely, or else Marty wouldn't remember him at all... unless it's just taking a little bit for the delayed ripple effect to catch up with him. Marty bites back a yelp at the thought--not only might Doc be gone, but Marty might not even so much as remember him in a few hours. Marty's life might be totally different, Doc effectively dead, and Marty he won't even remember his name.

Panic rises like bile in his throat. He reaches down, threads his fingers through Einstein's long fur, slowly petting him in an attempt to calm down. The dog jumps onto Marty's lap, and he's too big to be a lap dog, but he curls up over Marty's legs and the chair's armrests and his warm weight is comforting. "Thanks, Einie," he mumbles, and tries to think reasonable thoughts. It's way more likely that Doc's just gone to the store or something, he thinks. No reason to assume the worst.

Maybe the weird feeling in Marty's head is coincidental. Maybe the inability to feel him nearby has nothing to do with Doc being gone.

God, Einstein's never this clingy.

How long has Doc been gone?

Marty forces himself to take deep breaths. The initial panic passes and gives way to a lower-key feeling of dread. At least Einstein has calmed down, sound asleep and snoring softly on Marty's lap. Marty closes his eyes, repeats the same train of thought over and over again as he slowly strokes Einstein's fur. _I remember Doc. I remember Doc._

As long as he can feel Einstein's heavy weight on him, Doc still exists. If Doc didn't exist, Einstein would have been adopted by some other family, or not adopted at all and been put down in that shelter Doc got him from years ago.

Einstein yawns and closes his eyes. It's half an hour or more of silent waiting later when Marty follows his example, and he doesn't mean to fall asleep, but stress-induced, adrenaline-crash exhaustion takes him as soon as the panic wears down and his heart rate slows into something more manageable.

-

The still thing inside his skull jolts, heats, thrums into life.

There are wide, warm hands on his shoulders.

"Marty!"

Marty's eyes snap open and holy shit, there's Doc, in the flesh, with Einstein leaning against his legs and a brilliant grin on his face. "Doc!" Marty cries too-loud, springs to his feet, flings his arms around Doc's neck even though he has to jump just a little to reach.

Doc's shaking, buzzing with energy and he wraps his own arms tight around Marty, and Marty's holding him like a vice, like he's never going to let go. Doc's talking but Marty can hardly hear over the blood rushing in his ears. Doc's here and he's alive and whole and--

\--and Marty feels complete again, feels like the thing that was lost is back, he's got his missing piece and he never wants to feel like he's alone again, and more importantly he never wants to be without Doc, never again, and Jesus Christ, Marty's in love with him.

Marty pulls back when he realizes that Doc's still talking, stares up at him. "Doc, I didn't get _any_ of that," he says, "and I need you to explain--"

And Doc's got the same look on his face that he had when the DeLorean took its first test run in the mall parking lot, that eighty-eight-mile-per-hour grin, and he's still shaking when he grabs Marty's hand and laces their fingers. Instinctively Marty's fingers close around Doc's, not even questioning it.

"Teleportation! Easier to just show you!" Doc cries, all wild eyes and enthusiasm, "hold on and don't panic! Einie, we'll be right back. Brace yourself, Marty, it's not going to hurt, but it's a bit frosty!"

"Tele--Right back?" Marty knows that when Doc issues instructions in that tone of voice, it's best to follow them as soon as possible--he braces, for God knows what. "Doc, what the h--"

Doc wasn't kidding. There's a sudden burst of cold that bites all the way down to Marty's bones. He flinches, eyes closing reflexively against it. The cold is gone as soon as it appears, giving way to warmth.

Marty can feel the sun on his face.

He uncurls from the wince, eyes unscrewing themselves.

Clear blue water, powdery white sand under his Nikes, salty sea air and the sound of the waves crashing delicately against the shore. The garage is long gone.

"Holy shit, Doc," Marty says, faintly, still gripping Doc's hand, "holy _shit_ , where are--how--?!"

"Hawaii! And we _teleported_ , it's what I've been working on all day, after you appeared in my bed I thought maybe--just maybe it was possible to do _deliberately_! And it is, Marty, it _is!"_

Marty's head is spinning, he takes a few deep gulps of air and tries to form a thought. "We can teleport?" he finally manages, swallowing hard and staring out at the horizon. "And you--you showed me by taking me to Hawaii?"

"Why not show you with some style?" Doc positively giggles, gesturing widely out at the ocean. "The whole world, Marty! All of time and space, all for us!"

"Yeah, Doc," Marty says, and that joy Doc's feeling is contagious, the wonder, the exuberance. "All for us, all right, but--take me back to the garage, Doc," he continues, "Einstein's gonna--gonna be freaking out. _I'm_ freaking out. Holy shit, Doc--"

"Hold on," Doc says, and there's that burst of cold again, and Marty can't keep from clamping his eyes shut and wincing against it. When he opens his eyes, the garage surrounds them once more. Marty's brain feels dislodged from his skull, his chest too light, darkness and colors eating at the corners of his vision, and thank God the couch is right behind his legs because if it wasn't he would have collapsed on the floor.

-

"The _current_ theory," Doc says, "is that when the flux capacitor exploded, the electrical current vaporized us and scattered us all the way across time and space."

Marty wasn't unconscious long--maybe half an hour. Doc had let him sleep, chalked it up to 'jet lag' when he woke up. ("Happened to me when I first traveled too! Don't worry!") Doc's been excitedly explaining his findings ever since Marty woke.

"Wait," Marty says, leaning forward and staring up at him incredulously, "wait a minute, Doc, did you just say it _vaporized_ us? We're _dead_?"

"Oh, no! No, in fact, we're the two most alive people on the planet, Marty! All that happened is that parts of us were thrown from Hell to breakfast--we exist everywhere now! All we have to do is stop being one place and start being another. In a very real way we're already _there_."

"I guess this explains how I ended up in your bed," Marty manages after a few moments, Doc's on the sofa with Einstein, who's overjoyed to see him again. The dog's front paws are on his lap, and he's shoving his head against Doc's hands.

"Yes, it does," Doc explains, "you must have faded out in your sleep and been dreaming of being in the garage-you faded back in right here!"

"Is that how it works? You just fade out and back in?" When Doc nods, Marty continues. "So--so where were you? Where did you go?"

"Zipped around the garage a bit, really spooked Einie," Doc says with a lopsided smile. "The possibility for practical jokes here is monumental, Marty."

At that, Marty bursts into laughter. Doc figures out he can teleport with sheer force of will and one of the first things he does is map out the possibility for pranks, and Jesus Christ, Marty's so in love with him.

"Well," he says once he gains control of himself again, laughter still coloring his words, "I guess you did find something else to hold your attention, huh?"

"Instant travel should keep us occupied," Doc says lightly, a wry smile on his face, "we could go anywhere, all the great wonders. The Eiffel Tower, the Leaning Tower of Pisa, the Great Wall, Disney World--"

"Disney World, a great wonder?"

"Have you ever been?" Doc's eyes positively glitter. "Do you want to? There's quite literally nothing stopping us."

"How about we do Florida another time, Doc, and for now we tackle some dinner and you explain this in a little more detail?"

-

"It wasn't a dream after all," Marty says over his lo mein, "that weird cold place you're describing. We've been there once before, Doc, the night the capacitor blew up."

Doc looks at him sideways. "I... I suppose we were. In fact, the capacitor must have exploded while in the not-space, that must have been how we were flung around. This supports the theory," he says, quietly, almost to himself, then asks "what do you remember? It's a complete blank for me."

"Not much," Marty confesses. "We were there a while, I think? I think I had to find you." He takes another bite of his noodles. "So--to teleport, you fade out, go to the... the cold place, and then find where you want to go and fade back in?"

"I did it that way once," Doc says, "though it's easier to just start being somewhere else and then stop being here. Cuts out the middleman."

"But _how_?"

"Beats the shit out of me," Doc shrugs, "it's impossible to explain, it's like--it's just something you do," he says. "You'll get the hang of it."

-

Marty sleeps well, genuinely well, for the first time in a long time. His anxiety is at an all-time low, or at least that's how it feels. For once, they have a few answers--at least they knew why they were fading out, at least they know how Marty ended up in Doc's bed.

The one thing Marty still doesn't understand--that strange warm resonation in his chest and skull--is a source of comfort rather than worry. It means Doc's nearby. It's a mystery, but it's one that Marty's okay with for now.

-

"So I just imagine bein' over at that side of the garage, then, what, click my heels three times and say there's no place like home?"

"Feel the doormat under your feet! See the clocks! Stop being here, start being there. Or start being there and then stop being here, really just personal pref--"

"But how?"

Doc steps over and takes Marty's hand. "Like this," he says.

_easy easy loosen up don't panic don't worry Marty you'll get it_

Marty's expecting the blast of cold this time, and he manages to keep from flinching. In an instant they're standing at the other side of the garage, and Marty's still not sure how it happened. "Can you do that slower?" Marty asks, and Doc seems to think for a little bit.

"I can try," he says. "So first start being over there..."

That cold feeling washes over him again, slow this time, creeping up his body. Time seems to dilate--Marty inhales sharply as his awareness is split across two places, his mind struggling to handle input from four eyes--and then the mat under his feet disappears entirely and they're back in front of the huge amp.

"Great, so I know what it's supposed to feel like. Still got no idea how to actually do it," Marty says, and Doc pats him on the back.

"You'll get it, it's a matter of experimentation, perhaps it's different for you than it is for me? Perhaps practice fading out first?"

"I'll work on it, Doc."

-

Marty's been trying to ignore the realization that he's head-over-heels for Doc Brown, because that's inconvenient and terrifying if only because he's not sure Doc loves him back; better to not risk their friendship, in the end.

Still, it's hard to ignore, especially during times like this. They're standing at the edge of the Grand Canyon, staring out at it, wind blowing in their faces.

"This is heavy," Marty says, awestruck. He looks up at Doc, and Doc's smiling at the world like he's in love with it, and Marty tries _really_ hard to ignore the warmth curling in his chest.

"It's beautiful," Doc says.

"Yeah," Marty replies, "it is."

They can go anywhere, and the freedom is overwhelming in the best of ways, and Marty can't get enough of the world. He breathes it all in with the biggest lungfuls he can, and he can't get enough of Doc, either.

"Now what?" Marty asks, "Paris? New York?"

Doc looks down at him and there's this ridiculous depth of fondness in his eyes and Marty, for a second, is afraid he might drown there. "We've been here all day long, I think now we go _home_ ," he says. "It'd be easy to get overwhelmed with this, Marty, best to stay rested and not burn ourselves out."

"C'mon, Doc, the second you had the DeLorean working you went joyriding into the future and didn't look back!"

"And that worked out wonderfully with absolutely no negative impact, as we all know," Doc says with a playful quirk of his mouth. "Marty, the entire world is laid out for us! We can afford to take it slow. It'd be a shame to get jaded and numb to it all, you know." A pause. "And we still aren't sure what effects prolonged travel will have on us. Perhaps we'll be jet-lagged even worse."

"Alright, alright, you've got me there," Marty grumbles, nudges against Doc's side. "Let's get out of here."

-

"So," Marty says casually as he settles down next to Jennifer, back in their spot out on the quad. "Remember when you said _of course it can't be teleportation, Marty?_ "

Jennifer slams down her bottle of Coke so hard the metal picnic table rattles. She turns her head and fixes her dark eyes on Marty's. "You're _shitting_ me," she says severely, and Marty shakes his head.

"Doc and I went to the Grand Canyon this weekend. Traffic would have been a pain except, oh, wait, we didn't have to--"

"You're a mutant, that's it, my ex-boyfriend is a _mutant_ ," Jennifer says, "call Professor X, time for you to go to Mutant School." She pauses. "McFly, I swear, if you're playing me--"

"We took pictures," Marty says, "honest, Jen."

She lets out a breath, stares into the distance. "This is heavy," she says. "Can you show me? The teleporting, I mean."

"Well," Marty says, rubbing the back of his head, "I don't really know how? Doc can. He can take me with him when he does it, but I can't--I can't do it on my own yet. Not deliberately, at least."

"So _Doc_ can show me," Jennifer says. "I'm coming over later. I gotta see this." She picks up her Coke with hands that are only shaking a little bit, takes a sip before setting it back down. "You know," she says after a moment of silence, "you'd better figure this out fast. We're gonna be graduating really soon, so you've only got a little more window of opportunity left to pull pranks on Strickland."

 _Jesus Christ,_ Marty thinks, laughing so hard his stomach hurts, _I have a type. Brown-eyed, too-good-for-me geniuses whose first thought is 'pranking' when they hear 'teleportation.'_

-

A few months pass in relative peace. Every week or so, Doc and Marty will take a trip somewhere--New York, the Rock and Roll Hall of Fame, Thomas Edison's winter home, the Smithsonian. They take it easy, see it all, trawl through the museums and the streets. Marty knows enough broken French from last semester when he took it as an elective that they got along okay in Paris, and Doc knows just enough German that they were okay when they took a jaunt to Munich, where Doc's parents were from.

Figuring out he's in love with Doc wasn't so much of a surprise as it was a feeling of _oh, right_ , like pieces falling into place. It's been this way for years and he's just now realized it.

He tries to keep the thoughts hidden, in the back of his head when he's around Doc--Marty still gets the uneasy feeling that he and Doc can read each other's minds, to an extent, and it might be ridiculous, but Marty doesn't want to risk it.

-

The McFlys don't go too nuts on birthdays, and that's fine with Marty. He's not too fond of parties, anyhow--too many people--so cake and ice cream with his immediate family is the perfect amount of low-key celebration.

"It seems like just last week your mother and I were turning eighteen," his dad says over a mouthful of ice cream, and Marty nods.

"I totally understand," he says with absolute sincerity, and Linda snorts.

"Yeah, yeah, 'cause you're so old. The big one-eight, a foot in the grave and the other on a roller skate," she drawls, then tosses him a hastily wrapped package. He catches it out of the air.

"Thanks," he says, fingers digging at the paper and tearing it open.

Linda's given him new wheels for his skateboard--"because yours are nearly worn through, dipstick"--his mom gave him underwear, his dad a watch and Dave a gift card for the record store--"I dunno what the hell kinda shit you like nowadays, Marty! Pick it out yourself!"--and Marty can't shake the feeling of how lucky he is.

Even now, after all the revisions, his family is still a little weird--but god, Marty wouldn't want it any other way. They work now.

-

"You're the birthday boy, you shouldn't be helping me clean up," Marty's mom gently scolds. Marty ignores her and keeps loading up the dishwasher.

"C'mon, Mom. It's nothing, don't worry." A pause. "Besides, I might be trying to win you over, so I can ask you something."

She fixes him with a look, and her mouth quirks. "Oh, really?"

Marty puts a few more plates in the washer before he loads in the detergent and lights it off. "Doc wants to see me," he says, "I think he's got some birthday thing planned. So I--"

"Go, go," she says immediately, "Of course you can, it's--you're an adult now, anyway," she says, wistfully, and Marty smiles, kisses her on the cheek. "Go be with your friend."

"Thanks, Mom."

"I'm glad you told me instead of just leaving, though," she adds, "remember that, all right?"

"Yeah, mom."

-

The new wheels make his skateboard feel smoother, they make the ride easier by a lot. It had been a thoughtful gift--Marty hadn't even realized how worn-down the old wheels had become, but apparently Linda had.

 _Big sis, lookin' out for her dumb baby brother_. Marty can almost hear her voice. _Someone's gotta, huh?_

He could have driven his truck, he supposes, but it seems like a waste of gas to drive it when he can just as easily skate and catch rides on bumpers. Either way, he arrives at Doc's garage in good time, tries the door and finds it unlocked. "Doc?"

"Happy birthday!" Doc cries, launching up from his spot at his work table, bounding over to Marty and giving him a quick hug. Marty squeezes back, smiling automatically at the gesture.

"Hi, Doc. What's up?"

"Well--" Doc pulls back, bounds again over to his work table. "I did fix the hoverboard!"

"Fix it?"

"It now will run on water, and in fact will give you much more altitude if you so command," Doc enthuses, "but that's not my gift to you."

Doc looks like he's just about vibrating out of his skin. "And...?" Marty prompts.

"There's a meteor shower tonight," Doc says, "and here in Hill Valley you can't see them because of all the light pollution, but I thought we could go somewhere very remote and just--watch?" A pause. "If you wanted, that is. If--"

"That sounds great, Doc," Marty says, "I don't think I've ever seen a meteor shower."

Doc lights up again. "Well, in that case, are you ready to go?"

"Yeah, I"m ready when you are." Marty steps closer to him, holds out his hand for Doc to take. "I've been trying to practice teleporting but it's still not working for me."

"Well, we know you can do it," Doc says, apparently not discouraged in the slightest. "Have you gotten the hang of fading out on command?"

Marty shakes his head. "No breakthroughs. I can do it a little but it's nothin' spectacular."

Doc takes his hand. "You'll work it out," he says, assuredly. He slips his fingers between Marty's, flashes a bright smile. "Hold tight," he says, and Marty squeezes his hand in response, nods, and then there's that blast of cold, that feeling of _unspace_ before he rematerializes, easy as can be, under the night sky.

They're a fairly open area, field or clearing, surrounded by trees--probably a state park, from the well-maintained feel of it. It's also dark as hell; Marty blinks repeatedly as his eyes adjust. There's already a blanket under them, spread over the grass--one of Doc's old quilts, the one his mother made--and when Marty turns his eyes skyward he's a little taken aback.

"Wow," he breathes. "Wow, you can see the Milky Way."

Doc nods and settles down on the quilt, lying on his back with his hands folded neatly on his stomach. "Keep watching! You're sure to see a meteor soon. The shower's hitting peak in about ten minutes."

Marty lowers himself to the ground, sprawling out on his back next to Doc. He fights the urge to grab Doc's hand, instead focuses on how close they are already, how he can feel Doc's warmth radiating off of him, how something inside Marty resonates and thrums with their proximity.

Marty's pretty sure he could do it, and it'd be easy. All he'd have to do is prop himself up on his elbow, lean over, and kiss him. It'd be easy. It'd be so easy--

\--so easy to ruin their friendship and make sure that nothing would ever be the same between them.

"Look!" Doc cries, pointing up. "Did you see?"

"No, I--"

Just as Marty's about to say that he didn't see it, another one happens--a small streak of light across the sky, bright and unmistakable. "I saw it!" he says, laughing, "wow, holy hell, it's so pretty!"

Doc excitedly half-giggles, nudges him with his elbow; as soon as the contact is made Marty gets a blast of emotion, bright and pleased and satisfied.

Marty's eyes rove the sky, watching, waiting. "Doc," he says quietly, "have you noticed--weird stuff, weird brain stuff that happens whenever we touch each other?"

Doc hums thoughtfully. "I take it that the empathic bond hasn't been all in my head, then," he says slowly, and Marty's heart stops.

"How--how does it work for you? I can feel _feelings_." A pause. "Sometimes I can make out a few words," he adds softly, hesitantly, like a confession.

"Oh, I never get anything that clear," Doc says, and Marty lets out a huff of breath, a relieved sigh. "Mine are more sensory than verbal."

"How so?"

"Bars of song," Doc murmurs. "Usually."

Doc hears music when Marty touches him. "So throw another mystery on the pile. Weird mind-reading."

Doc shrugs. "What's another mystery at this point? At least the teleporting is mostly understood now. Or," he adds thoughtfully, "at least, how to _use_ it is mostly understood."

Another fireball races across the sky and Marty gasps in delight, shivers as another chases right on its tail. They're coming more frequently now, lights streaking against the darkness, out there in the vastness of space, and it's breathtaking. It might be the most unusual thing Marty's ever done for his birthday, but it's definitely the best, too. Marty shifts so he's closer, so that their arms are brushed together, and Marty wonders what the music is like this time.

-

Marty's at the breakfast table the next morning, chomping on a mouthful of Frosted Flakes. His dad sits to his left, leafing attentively through some sci-fi writer's magazine as he picks at his own toast. Mom's already left the table, Linda and Dave were gone when Marty woke up.

Marty swallows his bite of Frosted Flakes. "So, Dad," he says, and George looks up at him with that same earnest interest as always.

"Yes?"

"I gotta register for Selective Service now, right? How do I--"

"No, Marty, don't worry," his dad says, shaking his head. "You don't have to do that until you're eighteen."

Marty freezes, ice flash-freezing around his heart. "Yesterday _was_ my..." He falters, the words dying in his throat and lodging painfully there.

George laughs, fondly pats Marty's shoulder. "Forgetting how old you are, Marty? Taking after your father, I see," he says jovially, and Marty wills himself to stay put, not shoot up from the table, damn the cornflakes.

"I guess," he says, and he's proud that he manages to force out words at all, let alone keep his voice steady. He takes a few more bites of cereal before he does stand up, transfer his dishes to the dishwasher and bolt to his room as fast as his legs can carry him.

His wallet. His _wallet_. Marty casts about for it for a second before he spots it on his desk and snatches it up, flipping it open with shaking fingers.

He reads the date of birth on his driver's license. He reads it again. He closes the wallet, opens it back up, blinks a few times, and reads it once more.

Marty sets his wallet down and with trembling hands he reaches for the phone on his bedside table, carefully dials the number for Doc's garage phone.

"Marty?" Doc asks after two rings, because Marty's the only one who ever calls him. Marty swallows hard.

"Doc, my parents think I turned seventeen yesterday."

There's a pause. "Are you sure?"

"My driver's license is sure," Marty says. "I--it'd be cool if you were at the front door in about two minutes because I really wanna see you but I don't really trust myself to drive right now."

Doc hums into the receiver. "Of course. Two minutes, Marty."

Marty's in his room only long enough to get his shoes on, then down to the front door. Doc's there when he opens it; Marty closes the door behind them both, and Doc wordlessly takes his hand, and at this point the blast of freezing cold is almost a comfort.

They rematerialize in the garage, and immediately Einstein is there and throwing himself against Marty's legs, and maybe Marty was swaying unsteadily because both Doc's hands are on his shoulders. "It says I was born in 1970, Doc," Marty says, "we can't have gone anywhere to change it. What the hell is going on?"

Doc looks uncertain a second, his mouth quirking. "I... I don't know," he says, "I--"

Something clicks, jolts into place in Marty's head. "Doc, have you had a haircut since the capacitor exploded?"

Doc looks taken aback, bewildered. "I--"

"Because I haven't," Marty says, pieces falling into place, and he starts to shake, takes in a deep gasping breath before he says the next words. "Doc, I've been seventeen three years now and my hair hasn't grown an inch and I think--I think we're _immortal_."

"Great Scott," Doc says, blinking rapidly and staring into the middle distance. "Great Scott," he repeats, stepping back, running a hand through his hair and casting about for a second like he wants to run before his hands drop to his sides and he seems to halfway crumple, leaning his shoulder against the wall for a moment before he makes his way to the armchair and folds into it. Marty sets across from him, on the couch, just as floored; Einstein seems to sense their distress and paces unhappily between them, whining softly as his nails click against the concrete.

Doc's the one who breaks the heavy silence. "It fits," he says. "It _fits_ the puzzle."

"How does it fit, Doc," Marty asks wearily, "you gotta tell me."

"We were scattered across time and space, so we exist everywhere, and nowhere. So we've become--" Doc gestures for a second before his hands flop down. "Universal constants, stuck in a state of flux, in existence and yet not. If we're constants, then we aren't aging, and the universe scrambles to keep things coherent--thus the apparent birth date changes and the discrepancies in the memories of those around us."

"W--What about when my parents are eighty, ninety years old and they still think I'm seventeen? Doc, this has gotta collapse at some point, this can't--"

"Marty, I haven't the faintest _clue_ how it's going to work," Doc says, and he sounds absolutely pained, "but apparently we're going to have the time to figure it out."

-

Marty gets to class late. He can't pay attention in any classes, he can hardly remember walking from one room to the next; he moves as in a daze, numb, bewildered.

Jennifer wishes him a happy seventeenth birthday when she seeks him out at lunchtime in the campus student center. They've graduated high school now, and they've orchestrated taking their pre-requisite classes at Hill Valley State College mostly together. The only classes they don't have together are Marty's music electives.

"What's wrong, Marty, you've looked like you've seen a ghost all day long," she says, and Marty wants to explain to her, wants to tell her what's going on. Christ, he wants to tell her. He wants to tell her, but he doesn't know how to word it.

"You remember the teleporting stuff, right," he says slowly, and Jennifer's eyes widen as she nods.

"Yeah, of course," she says. "I've seen it happen, how could I forget?"

"Do you remember the rest of that conversation?"

"Well, yeah, it was..." she pauses, stares into space a second. "I mean--yeah, something about... your driver's license? How old you were? I don't--" She rubs her forehead, her brow furrowing. "It was months ago, Marty, it's kinda fuzzy." She looks back at him. "Why? What's wrong?"

Jen, your brain's scrambled because I'm not aging and the universe is trying to force it to make sense in your head. I'm immortal, and I'm gonna watch you, and my parents, and my sister and brother and everyone on this planet die.

"Nothing's wrong." Marty forces a smile, lopsided and casual, and oh, he's too good at it. "Just tired, I guess. Music Theory's killing me."

"God, tell me about it," Jennifer groans, "it's gotta be better than Chem."

-

Chem is the last class of the day and it's late at night, too. It's nine PM by the time Marty's in his truck and leaving the college parking lot. At least it's only two nights a week. "Never doing this again," he groans to himself, as he always does when he leaves this class and begins home. Late classes aren't something he likes under the best of circumstances.

Tonight was especially hard. It's tough to focus on ionic bonds when you're worrying about the spacetime continuum and remembering that if you have kids, grandkids, great-grandkids, you'll outlive them all.

He's going to outlive Jennifer, he's going to outlive his parents and his siblings and all the Pinheads.

The only one he's not going to outlive is Doc.

Marty swears and slams on the brakes to keep from running a red light. He shakes himself and tries to shove the heavy thoughts from his head, focus more on the road. Immortal or not, a car wreck isn't something Marty really wants to experience.

He automatically navigates to Doc's garage, pulls into the driveway and parks his truck next to the DeLorean before he makes his way to the door, moves to get the key form under the doormat; he unlocks the deadbolt and turns the knob, nudges the door open.

"Hey, Doc," Marty calls as he steps inside. He sees Doc immediately; he's studiously organizing a shelf that looks like it hasn't been touched in years. Jesus, he's organizing something. He must be really shook. "How're you holding up?"

"Hi, Marty," Doc greets him, up to his elbows in god knows what. "I'm perfectly fine, how are you?"

"Doc, you're organizing your drill bits by size," Marty says, looking closer. "You're not fine. I know better."

Doc takes a deep breath, his hands stilling, the frenetic energy seeming to melt from him. "I've just been thinking on our--situation," he says. "How we're in a state of constantly turning the same age. It's--I suppose if we were going to cause the end of the universe as we know it we'd already have done so. So there's that," he says, and he looks miserable and apologetic and it occurs to Marty again that Doc's the only person he's not going to outlive.

Marty's got his arms around the man before change his mind. With Doc sitting, Marty's taller, and he rests his chin atop Doc's downy white head. Doc draws a rattling breath before he relaxes, rests his head against Marty's chest and wraps his arms around him in return. "The good news is," Marty says, "we've got lots of time to figure it all out now, right?" and he's aiming for humor and he must hit it because Doc huffs a little laugh as he pulls back.

"That we will," he says. "All right, now where did you put that hoverboard of yours? There's an adjustment I need to make."

"Aw, really?" Marty steps back to grab the board from where it leans against the wall. "It just got back together and you're takin' it apart again?"

"I can leave it the way it is if you want to go shooting into the atmosphere when you ask it to gain altitude too quickly," Doc says, deadpan, and Marty hisses.

"Eeeh. No, yeah, probably a good idea to go ahead and make that adjustment," he says, and hands him the hoverboard.

-

It's past midnight now. Doc quit work on the hoverboard a while back and now they're on the couch and they're almost at the end of the second Star Wars. Einstein's doing his best impression of a lap dog on Marty, and Doc's eyes are half closed by the time the movie's over and the credits roll. Einstein's snoring, Doc's yawning, Star Wars theme music is playing softly from the old TV--Marty's warm and comfortable and for a little while he forgot that nothing was ever going to be the same.

Neither of them make a move to get up from the couch. It's late and Marty should go home, but the nervous energy hasn't quite dissipated, they're both still upset, and it doesn't seem right to be apart. "I don't want to go home," Marty says.

"Then don't," Doc replies, clicking off the TV. He stands up and moves across the garage, leaving Marty with Einstein. When he re-enters Marty's field of vision, he's in his sleep clothes and he tosses Marty a too-big tee shirt and a pair of way too-long waffle weave drawstring pants. The clothes land on Einstein, who doesn't so much as twitch. Carefully Marty ousts Einie from his lap. The dog grumbles and flops onto the couch beside him, and Marty takes the clothes to the bathroom to change.

Doc's in his bed by the time Marty returns, apparently half asleep. Uncertainty grips him. He eyes the couch, the armchair, then... fuck it. Fuck it, he doesn't want to be alone. He creeps over to the bed and settles down beside Doc, curling up under the covers.

Doc's not quite asleep, Marty can tell. Warmth radiates from him, transmits over their bond. "Thanks, Doc," Marty says quietly. "I just didn't wanna be alone tonight, you know?"

"I didn't either," Doc replies, and rolls over to face Marty. "You're always welcome here."

Marty nestles up beneath Doc's chin, like Doc did with him earlier and so unlike how they slept next to each other last time. Doc doesn't tense up, doesn't seize like he did when Marty hugged him in 1955. He's used to the affection by now. A big hand slides up Marty's back, thumb moving back and forth, stroking comfortingly, slowly.

Christ, Marty's so in love with him. And it's not like things can get any worse now, really, and--hell, the age difference never meant anything to Marty, but now at least there's no worry about one outliving the other, and Marty feels a tiny rush of relief about that, that at least they're dealing with this _together_.

"Doc?" he says, and Doc pulls back to look down at him, puzzled.

Better Judgment cries at Marty to stop, to not do what he's thinking about.

"Hm?" Doc hums, curious, and Marty tells Better Judgment to cram it.

His last ounce of uncertainty and fear of rejection means it's hesitant, means it's slow, but all it takes is Marty tipping his head up and kissing him softly to make that fear disintegrate. The second they make contact, their resonation sparks violently, blinding and warm. Doc shivers and tenses before he absolutely melts, kissing back, and Marty can feel him trembling, can feel love shining halogen-bright, and the last time Marty felt this was in the Unspace, was when Doc agreed to come home, and Marty's only just now remembering it. Joy lances through him, bubbling up in his chest, and everything's gone to hell but Doc loves him, Doc _loves_ him like he loves Doc, and they're kissing, and Doc's hands are still at his back, holding him close.

And then, suddenly, Doc stills. The light fades and gives way to a red haze, confusion that leads to terror, and Doc pulls back, stares into Marty's eyes like a spooked animal. Before Marty can say anything, Doc's already speaking, waves and waves of fear and sorrow and regret underscoring his words.

"My God," he says, voice shaking; he yanks his hands away from Marty as if burned. "My God, I've trapped you with me."

Marty's reeling and Doc's thrown himself from the bed, backing away from Marty as fast as he can, and the last time Marty saw him fling himself away from him like this was when he shouted _1.21 gigawatts!_ in 1955. "Doc, what--I don't understand," he cries, and Doc shakes his head.

"I've doomed you, Marty, I'm so sorry," he says, and Marty's scrambling from the bed, trying to get closer, and he can't say another word, can't even get out _no, that's not it_ , Doc before Doc's _gone_.

Marty barely processes that Doc's split the scene before he feels the resonating, moving thing in his skull shudder to a stop, unnaturally still. Frosty cold seems to emanate through his body, that feeling of something missing, and Marty collapses heavily back onto the bed.

Doc's gone.

Marty gasps in a few breaths, forces himself to stay calm. Doc will come back. Doc will come back, and Marty can--can tell him he's wrong. Can tell him he hasn't done anything bad.

He'll come back.

Shivering, Marty curls into a little ball on Doc's bed. Einstein is there immediately, taking up blanket duty, clingy like he was when Doc left before.

He'll calm down, and he'll come back. He has to.

Marty stays up as long as he can, eyes resting on the digital clock across the room. It's a long while before sleep finally wins.

-

Doc's still not around when Marty wakes up only a few hours later, his sleep broken by anxiousness that stuck even in dreams. The clocks tell him it's two-thirty AM. He's been asleep two hours, if that.

"C'mon, Doc," Marty says into the air, sitting up and looking around, brain trying to settle and rearrange around the weird, still thing there.

"Boof," Einstein says, and Marty reaches down to pet the soft fur behind his ears.

"I know, buddy," he says. "I'm gonna go look for him."

The only problem is, Marty thinks, Doc's nowhere close by. The last time Marty felt this loss, Doc was at least as far as Hawaii. Marty figures he should at least check their usual haunts, or the ones Doc likes--the ones he goes to when he wants to think--but Christ, he can't teleport on his own and he has no way to get there.

"Can you teach me to teleport?" Marty asks, staring down at Einie.

"Boof," Einstein says a little louder.

"Yeah, I already know I'm a jackass, you don't have to tell me," Marty grumbles, and stands up. "All right. Okay, McFly. Just stop being here and start being there. Easy."

God, what does that even _mean_? What's he supposed to even do? He closes his eyes, tenses every muscle in his body, and--

Nope. Nothing but a cramp in his leg. "A pair of ruby slippers would be great right now," Marty grumbles to the garage in general. "How come I can only do this in my sleep?"

"Aaou-rawoo," Einstein supplies, an aborted half-howl. He trots over and bunts his head against Marty's leg.

"Thanks for the pep talk, Einie." Marty reaches down and scratches the scruffy fur at his neck. "You're right, I gotta stop feelin' sorry for myself. Try try again, right?"

He pictures the other side of the garage, orders himself to go there over and over again in his mind. The other side of the garage. The clocks. The jukebox. The--god, but he can perceive those from /here/ already.

Still, nothing except maybe the start of a headache on top of the cramp in his leg.

Frustration builds in Marty's chest. He takes a deep breath before he takes a long-enough break to feed Einstein.

-

He's been at this for a few hours now and it's nearly six in the morning, and he has class starting at eight AM, and he's going to get a shitty participation grade at this rate, but as far as Marty's concerned, his professor can bite his ass. Marty's tried everything he can think of and he can't so much as teleport an inch, let alone get all the way across the garage.

He's close to being hysterical now. Doc's still gone, and--

Christ, is he ever gonna come back?

Marty swipes a few frustrated tears from his eyes with the heel of his hand, takes a deep breath and straightens up.

 _Think, McFly. What were you_ dreaming _about when you showed up in Doc's bed?_

He pulls back the hazy, pleasant memory with ease. Warmth, softness, the smell of Doc's detergent and shampoo. All of it is intense sensory detail.

Intense detail. The smell of Doc, the warmth of his body, so different from Marty's own empty bed.

And yet the garage feels pretty much the same on the other side as it does on this one. Holy fuck, maybe that's it. Frantically, Marty latches onto the place most different from this lab that he can imagine. He remembers the heat on his face, the feel of stone beneath his feet, the cool breeze and the hot sun and the smell of fresh air so different from here.

The Arizona landscape explodes into view, flickering like an old TV picture, and he feels coldness creeping at him and then just as fast he slams back out of it, gasping so hard his throat hurts and his lungs burn. He's in Doc's garage again, heaving, panting, doubled over with his hands on his knees as he struggles for air and tries to will his heart to stop beating so goddamn fast.

That's _it_ , that's the key, the sensory details. Jesus, maybe that's why Doc is so goddamn good at it, he seems to feel _everything_ , catalog every tiny fraction of input he gets. Or maybe there's another way to do it, and this is just Marty's, but--

 _Slow down, McFly. You haven't done it yet_. His heartbeat is down to a more manageable rate now, at least, and he's got half the puzzle down. Obviously he's started being somewhere else, and now the second part of the parlor trick is to stop being here.

"How the fuck," he says out loud.

"Wuf," Einstein whispers, chin on his paws.

"Uh-huh," Marty replies, and tries again. Arizona. Desert, sandstone, wide blue sky.

Again the landscape bursts into his vision and this time he's expecting it and catches it, holds on as tight as he can. _C'mon, McFly, you're there, you're there, you don't feel the concrete floor or the breeze from the heating vent. You just feel--_

The familiar blast of cold, then absolute silence.

Marty cracks his eyes open.

He's standing at the South Rim of the Grand Canyon at six in the morning in Doc's pajamas.

"Holy shit," he gasps out, then grins and laughs hysterically, triumphant. When he hops in an excited little circle, he steps on the cuffs of his too-long pant legs. "Holy shit, I _did_ it!"

Well, okay, he's here in his pajamas, and maybe he should have put on real some clothes before he did this. This is Doc's favorite spot, anyway, and he isn't here. If he was anywhere nearby, anywhere at all, Marty would know it.

Now to get back to the garage, put on some clothes, and try again.

-

Marty tries every place he can imagine. The beach in Hawaii. Thomas Edison's winter home. The Smithsonian Natural History Museum that Doc liked so much.  
  
The last place Marty tries is the top of the Hill Valley courthouse, right by the clock. Doc once told him that was where he liked to go to think, when he was a boy.

Still no matter what corner of the earth Marty goes to, he can't feel Doc anywhere. Marty reappears in the garage and sits down heavily on the bed, head in his hands. _Jesus Christ, Doc, you can't have just disappeared._ He should be able to feel Doc, he should be able to track him down. There's nowhere he could be.

Marty lifts his head, eyes roving back and forth as he thinks. _That's it. If he's not anywhere, he's gotta be nowhere. He's gotta be Nowhere. The cold place is the only spot I haven't looked._ Christ, he isn't even sure how to get there, and even if he did--the last time he was there is nothing but a hazy memory now, a half-remembered dream, but it had been seemingly infinite and Marty wonders if he could get lost.

If Doc isn't anywhere, he has to be nowhere, and Marty has to go get him. Just like last time. He did it once, he can do it again--if he's there, of course.

Reaching deliberately for a cold sensation doesn't cut it--those sensory coordinates are too vague, apparently. "Don't wanna end up in the Arctic, right?" Marty quips to Einstein with a joyless half-laugh.

 _Okay, so you just--you just stop being here without starting to be somewhere else. That's gotta land you in the Unspace,_ he thinks, _in theory._ But as he stands there, he finds it's hard to let go without something else to focus on. He can't even begin; he shakes himself, paces a moment as he thinks.

All right, one last shot that might work. One final Hail Mary. He feels for the Grand Canyon again. He feels for it, and begins to let go of the garage, slow, in creeping increments. His mind splits across the two places, his brain struggles to handle input from four eyes, and Marty closes them, closes them and struggles to stay in both places.

It's not sustainable. It's not sustainable, he can't do it long, he feels like it'll rip him apart. Convenient, he thinks frantically, getting ripped apart is what landed me there to begin with, right?

And as he's beginning to let go of the garage, right as the cold feeling starts to creep, he jettisons the Canyon entirely. He blocks every detail, he stops trying to go either place the second he's equally in both, and instead he grasps tightly to the biting cold.

It roars in his ears as it overtakes him, and in an instant he is consumed.

-

It doesn't hurt. It never does.

He expands and contracts, he shifts and coalesces.

How long has he been here?

 _Wow_ , he thinks, parts of his galaxy lighting up with it. He can perceive parts of himself, glowing sparks, drawing closer to his center. _This is... wow._

It seems like most of his pieces are in one place, now.

He can't feel Doc.

That's fine, that's _fine_ , he's still hovering around Hill Valley. He hasn't even gone looking yet.

He fears that if he spreads out, he'll lose parts of himself. But he's come this far, he isn't going to stop now. He expands, breathing in the inky nothingness, letting it fill the spaces between himself as he sends feelers out.

There is no way to gauge time here. Marty spreads wide, willing to search the entire infinite darkness if he has to, and perhaps he does.

It feels like it might be a long time. For immeasurable moments he trawls through the Unspace, skirting around spacetime and examining every instant, every possible place he could be.

And then, finally, a tiny crackle, the littlest spark, and Marty rushes toward it, his entire collective finding Doc's, and it seems almost lifeless, dark and dull and each little light so horribly dimmed--

\--and even so, Marty, the still piece of him thrums to life again, he feels warm even in this Unspace, and he can feel--he can _feel_ \--

Marty suddenly understands why they resonate.

There's a piece of Marty inside Doc's galaxy of consciousness already; it's there and it begins to react when it's nearby Marty's collective--and the _thing_ that rattles when Doc's nearby is a piece of Doc, carried within him, quite literally.

What a colossal mix-up, Marty thinks, and he makes no move to correct it.

 _go away_ Doc seems to cry when Marty draws near, _go away go away_

No, Marty sends back, and Doc seems to shrink, tense, all his collective folding in on itself.

_I never meant to trap you with me you deserve better I have to fix this somehow I have to fix this_

Fear, horror.

_I made it so I'm the only one you can stay with everyone else will die I made myself your only hope your only option it's not a choice at all now_

God, it couldn't be less true. Doc's jumbled thoughts and emotions are almost a wail, reverberating through the space, and Marty hates it.

 _You can't fix it and I don't want you to,_ Marty sends as forcefully as he can, overlapping with Doc, breathing warmth into him. _I've been head over heels for you since I was fifteen_ , Marty continues, and he feels Doc untense slightly, let Marty into the spaces between his fragments. _And there's nothing more I wanna do than dance across space and time with you forever, Doc_.

Uncertainty radiates from Doc's consciousness, but also--relief? Happiness, tempered by fear?

_since you were fifteen_

_I love you,_ _Emmett_ , Marty tries to convey with every single shard of himself, tries to convey it as loud as he can, broadcast it across the entirety of spacetime. _Come home._

The sparks that make up Doc begin to light again.

-

Concrete underfoot. Fresh night air, rays of sunlight just starting to touch the edges of the sky.

The garage sits before them, the driveway beneath them. They stand facing each other, Doc looking at him like he's seeing him for the first time, dark eyes soft and amazed. He steps forward, reaches up to cup Marty's face in his wide, work-roughened hands.

"How fortunate I am to have you," he murmurs, "how endlessly lucky." Warmth radiates in the negligible space between them.

"C'mon, Doc, kiss me? I've been waiting a while."

"I've been waiting thirty years," Doc says, and Marty stretches up and Doc leans down and they meet in the middle. Doc kisses him sweet and slow, all hesitance gone, and yeah, this has been worth the wait. "If I'm going to be facing down eternity, Marty," Doc says, pulling back enough to speak, "I'm glad to be doing it with you."

"The way I see it, eternity's facing down us, Doc. We've got a universe to watch over, and it's up to us to keep things in order."

Doc's thumbs stroke Marty's cheeks. Marty can feel that joy again, that frenetic energy that comes before discovery. He's not sure who it's coming from. Maybe both of them. Maybe it doesn't matter. "Then when shall we get started?"

"No time like the present." Marty flashes a cocky grin, reaches up to lay his hands over Doc's. "Where should we go? _When_ should we go?"

"Mr. McFly," Doc says, lacing his fingers with Marty's, "thrill me."

**Author's Note:**

> i have nothing to say for myself


End file.
